Motor function will be assessed by recording voluntary motor responses in the lower extremity. The investigators will grade plantar flexion and dorsiflexion of the foot based on the following scale: 0 = normal movement, 1 = decreased movement, and 2 = no movement. Motor block will be deemed complete when a score of 2 is recorded for both plantar flexion and dorsiflexion. This grading scale has been described before for assessment of motor function following popliteal sciatic nerve block.